Elucidation of protein transport mechanism in ion exchanges is essential to model separation performance. In this work we simulate intraparticle adsorption profiles during batch adsorption assuming typical process conditions for pore, solid and parallel diffusion. Artificial confocal laser scanning microscopy images are created to identify apparent differences between the different transport mechanisms. Typical sharp fronts for pore diffusion are characteristic for binding strengths as low as K = 1. Only at K = 0.1 and lower, the profiles are smooth and practically indistinguishable from a solid diffusion mechanism. During hold and wash steps, at which the interstitial buffer is removed or exchanged, continuation of diffusion of protein molecules is significant for solid diffusion due to the adsorbed phase concentration driving force. For pore diffusion, protein mobility is considerable at low and moderate binding strength. Only when pore diffusion if completely dominant, and the binding strength is very high, protein mobility is low enough to restrict diffusion out of the particles. Simulation of column operation reveals substantial protein loss when operating conditions are not adjusted appropriately.

A simple, nondestructive method for characterizing ionizable groups on a polymer matrix is presented. It is based on the pH transition formed by a step change in the ionic strength of buffer solutions. Either height or duration of the pH transition excursion was shown to be linearly proportional to the amount of groups determined by elemental analysis. The method can be applied to ion-exchange groups, but also to any other group of ionizable character, such as chelating groups. Recently, it was shown that the method can be extended to estimate the amount of immobilized protein.

Multi-column chromatography (periodic counter-current chromatography, PCCC) with protein A affinity resins is used as an efficient monoclonal antibody (mAb) continuous capture process. However, the evaluation of the efficiency of PCCC process compared with repeated batch (or cyclic) operation (RBO) is still not standardized. In this study, we proposed two criteria for evaluating the capture process efficiency, productivity P and buffer consumption per load amount, B_C. These criteria were calculated for 2 column, 3 column and 4 column-PCCC and for RBO. For PCCC, P was proportional to mAb concentration C₀ and inversely proportional to the number of columns, n_C since the loaded amount of mAb M_L was fixed for the calculation. B_c did not depend on C₀ or n_C as M_L was the same. For RBO, B_C was larger by 20% at residence time (RT) = 4 minutes, and by 50% at RT = 2 minutes whereas P was similar to or slightly lower than that for 2C-PCCC at the same RT (4 minutes).

The effect of temperature T on the chromatographic separation performance was examined by using a model separation system: polyphenol isocratic elution separation by polymer-resin chromatography with ethanol-water mobile phases within the temperature range 15-45°C. HETP decreased with increasing T. The reduced HETP and the reduced velocity plots can be approximated by a single universal curve. The equations describing the distribution coefficient K as a function of T were also developed. A simple equation was derived, which can describe the resolution of two components R_s as a function of T. R_s did not increase significantly with T while the separation time can be reduced.

Non-equilibrium molecular dynamics was performed to investigate the influence of the grain boundary region in CHA-type zeolite membranes on the permeability and selectivity of a CO₂/CH₄ gas mixture. It was confirmed that under the investigated gas pressure, the grain boundary was preferentially occupied by CO₂, resulting in an increase in the CO₂ selectivity and flux. The results indicated that a CHA membrane with a fine controlled grain boundary structure could exhibit increased selectivity and permeability for condensable gas species compared to perfect crystalline CHA membranes.

Chemical reaction formula does not provide information on size and morphology of formed solids. In this talk, we introduce our recent results on process-dependent changes in size and morphology of silicon solids produced via zinc reduction of SiCl₄. Silicon whiskers, microparticles and nanowires form in the reaction, in which zinc vapor reduces SiCl₄ and zinc droplets catalyse crystallization of silicon. Flow of gases in a reactor and temperature of substrate affect solidification processes of silicon. Effects of there factors on the formation of silicon whiskers and nanowires are discussed using both experimental results and numerical analysis.

The direct production method of H₂ gas from seawater using femtosecond pulse laser was developed. This approach uses the photolysis triggered by multiphoton absorption of H₂O molecules and does not emit greenhouse or harmful gas such as CO₂ and Cl₂. In this study, direct H₂ production from seawater without desalination was demonstrated, and influences of focusing lens and salinity on H₂ production were experimentally revealed with a gas chromatograph. Aqueous solutions with moderate salinity (0.1-4%) showed a positive effect on H₂ production owing to nonlinear optical effects by ultrashort laser pulses, while excessive salt (the salinity of 7.0%) interfered with the ionization of H₂O.